Question

What is the current in amperes if 1200 na+ ions flow across a cell membrane in 3.5 μs ? the charge on the sodium is the same as on an electron, but positive?

Answer 1

Answer:

$I=5.48\times 10^{-11}\ A$

Explanation:

It is given that,

Number of Na⁺ ion, n = 1200 C

So, total charge, $q=1200\times 1.6\times 10^{-19}\ C$

Time taken to flow the charges, t = 3.5 μs = 3.5 × 10⁻⁶ s

Electric current is defined as the ratio of electric charge per unit time.

$I=\dfrac{q}{t}$

$I=\dfrac{1200\times 1.6\times 10^{-19}\ C}{3.5\times 10^{-6}\ s}$

$I=\dfrac{1200\ C}{3.5\times 10^{-6}\ s}$

$I=5.48\times 10^{-11}\ A$

So, the current flowing in the circuit is $5.48\times 10^{-11}\ A$

Answer 2

Charge = 1200 * 1.6 * 10^-19 = 1920 * 10^-19 
Time = 3.5 µs = 3.5 * 10^-6 s  
But Current = charge/time = (1920 * 10^-19) / (3.5 * 10^-6) 
So Current becomes 548.5714 * 10^(-19-(-6)) 
So we have 548.5714 * 10^(-19 + 6) = 548.5714 * 10^(-13) 
So we have 5.485714 * 10^(-15)